Smoke detectors and time change.

[Rat407]

This is probably old new for some but during the time change, one is supposed to test or replace the batteries in their smoke detectors. But what most don't know is that if they are over 10 years old, they need to be replaced. I found one in our house that was right at 10 years old. So I upgraded it to a smoke/carbon monoxide detector since we have gas logs.

 

[JohnnyG]

Is that because the sensors for smoke lose their effectiveness, or what exactly?
I know my carbon monoxide/smoke detector (which is on a lower bookshelf, since CO is heavier that air) only has a battery good for 10 years. The battery itself is not replaceable, but the recommendation is to replace the whole unit.

OTOH, the smoke detectors in the rest of my house are hard wired, and have never been replaced! This house was built in 1994 and I suspect that they are original.
How would you go about addressing that situation? I have been suspecting that they should be replaced, but are not giving any warnings or errant alarms.

 

[CleanSump]

During the "time change" is just a date someone picked. They could have picked the Spring and Fall Equinox. Some fire departments say to check every New Years Day.

 

[Zee09]

I check mine after every fire

 

[kschachn]

Many new-ish ones beep after the 10 year period.

 

[Lubener]

Most of mine are getting old. I check them periodically with a smoke stick (punk). If they fail the test, then I replace them.

 

[SShooterZ]

Is that because the sensors for smoke lose their effectiveness, or what exactly?
I know my carbon monoxide/smoke detector (which is on a lower bookshelf, since CO is heavier that air) only has a battery good for 10 years. The battery itself is not replaceable, but the recommendation is to replace the whole unit.

OTOH, the smoke detectors in the rest of my house are hard wired, and have never been replaced! This house was built in 1994 and I suspect that they are original.
How would you go about addressing that situation? I have been suspecting that they should be replaced, but are not giving any warnings or errant alarms.

This is a great question and I am faced with the same dilemma. My house was built in 1993 and as far as I know, these are original. I know they work for smoke as when we start to burn a pizza, they most definitely go off. I doubt that have any CM detection in them though. Also hardwired and wondering what would be the best strategy to upgrade.

 

[PWMDMD]

I recently replaced all my smoke/CO detectors because they started beeping after 10 years (I think it was three beeps?) meaning they needed to be replaced. I replaced them with the equivalent model now sold but WOW, these things are SOOOOO sensitive. If cooking set the old ones off one or twice a year that was a lot and it was with visible smoke filling the room. These new ones go off 2-3x per week while we're are cooking with no visible smoke.

 

[bdc101]

@JohnnyG @SShooterZ Are you sure they have power over the hardwiring? I have only seen smoke detectors that were networked (i.e. they would tell each other when they were going off so all the rest of them would go off too) but still had batteries in them for power. Those are a pain to get adapters for when you need to replace the smoke detectors every 10 years and can't find the original ones to buy. But you can get them.

Either way I would consider just remove the originals all at once, and putting regular smoke detectors where they used to be. Tuck the wiring underneath the new one. If it actually has power, find out what circuit in your electrical panel feeds them and turn it off, or if there is a low voltage power supply feeding them, figure out where it is. I can't imagine they have 120v (but I've been wrong before).

 

[mk378]

Hardwired has always used the same wiring scheme: a bus of three wires: hot common, and a signal wire to each unit all connected in parallel. As long as you replace all of them at once with the same brand/model they should work with your existing wiring. Hardwired detectors normally run from the AC power but always contain a battery so they will also work during power failure.

Interconnection is a big advantage as you may not hear a detector in a distant part of the house.

 

[kschachn]

@JohnnyG @SShooterZ Are you sure they have power over the hardwiring? I have only seen smoke detectors that were networked (i.e. they would tell each other when they were going off so all the rest of them would go off too) but still had batteries in them for power. Those are a pain to get adapters for when you need to replace the smoke detectors every 10 years and can't find the original ones to buy. But you can get them.

Either way I would consider just remove the originals all at once, and putting regular smoke detectors where they used to be. Tuck the wiring underneath the new one. If it actually has power, find out what circuit in your electrical panel feeds them and turn it off, or if there is a low voltage power supply feeding them, figure out where it is. I can't imagine they have 120v (but I've been wrong before).

They are powered off of the 120v input. The third wire is the interconnect.

I would not use any adapters. Just take the pigtail out of the main wiring and put the new pigtail in its place. That way they do not have to be the same brand and you eliminate the extra connection than an adapter causes.

Nor would I replace them with solely battery powered units. Why would you do this? There’s a good reason for the interconnection.

 

[Klutch9]

CO detectors actually do expire. They lose their ability to sample the air after some time, usually 5,7,10 years. Whatever is stated on the box. They are required to give an end-of-life signal once they become paperweights. This was only a requirement that started in the last 10-15 years or so. I see old ones in customer homes all the time that are 30ish years old and still appear to work fine (no beeping).

Smoke detectors do not actually expire. The reason that building codes state to replace them anyway is because they can become dirty and/or deviate from their sensitivity range over time. Plus, for the longest time, most 120v smokes were ionization type, which would false-alarm if you looked at them sideways. And they were made cheaply. Now, we're starting to see more photoelectric smokes in the consumer space. These are more accurate and less false-alarm prone, and tend to be of higher quality in my experience.

I install residential and commercial burglar and fire alarm systems, FWIW.

 

[SShooterZ]

@JohnnyG @SShooterZ Are you sure they have power over the hardwiring?

I can't confirm TBH. They all have 9V batteries that will chirp when low. That said, I've had the detector go off in the kitchen area without setting the rest of the house off, so IDK that answer.

 

[mk378]

Most places now require interconnected hardwired detectors in new houses, but old houses are grandfathered. It is of course possible for someone to install detectors and not interconnect them. You may need to investigate exactly how yours are wired.

 

[alarmguy]

Just buy the same model and replace them. If that exact model isn’t available chances or something very similar with a similar plug is still available. All hardwire smoke detectors have batteries unless it’s a central alarm system with a backup power supply

 

[tbm5690]

I replaced all of mine a few years ago. 1996 build, had original detectors all hardwired together. New detectors come with wiring adapters so all you have to do is kill the power, twist those in with wire nuts, and then plug in and done. That said, if all of these start beeping simultaneously at 10 years that will be annoying.

Also note that there are multiple types of sensors in these detectors...best to get a variety and place them where they make sense. Some sensors are better for kitchen placement vs bedroom.

 

[dubber09]

One of my smoke/CO detectors reached EOL late last year, I pulled it off and checked manufacturers site for compatible/replacement one, there were 3 different ones. Old and new detectors are rated for 10 years of use, they are factory programmed to emit particular sound pattern when they reach end of life (10 years later) and you cannot disable the sound unless you dissect the detector.
I replaced 3 same old detectors in house. They are all interconnected, one on each floor. I went with one that has replaceable battery and two with 10 year batteries (bought as a 2 pack at Costco). Bedrooms have different detectors with 9V batteries.

 

[bdc101]

I can't confirm TBH. They all have 9V batteries that will chirp when low. That said, I've had the detector go off in the kitchen area without setting the rest of the house off, so IDK that answer.

Yeah, those are just interconnected to each other. The wires are there so that if one goes off, the others will too. You need to get something like this if you want to replace some of them and network them into the same system. https://www.homedepot.com/p/Kidde-Hardwired-Smoke-and-Detector-Adapters-21028461-21028461/309522936

 

[97prizm]

Is that because the sensors for smoke lose their effectiveness, or what exactly?
I know my carbon monoxide/smoke detector (which is on a lower bookshelf, since CO is heavier that air) only has a battery good for 10 years. The battery itself is not replaceable, but the recommendation is to replace the whole unit.

OTOH, the smoke detectors in the rest of my house are hard wired, and have never been replaced! This house was built in 1994 and I suspect that they are original.
How would you go about addressing that situation? I have been suspecting that they should be replaced, but are not giving any warnings or errant alarms.

Kidde and X sense have a hardwired smoke detectors that I think now can relay to each other from what I've seen. If smoke is detected in the bathroom it can set off detectors in other rooms to alert people.

 

[kschachn]

Yeah, those are just interconnected to each other. The wires are there so that if one goes off, the others will too. You need to get something like this if you want to replace some of them and network them into the same system. https://www.homedepot.com/p/Kidde-Hardwired-Smoke-and-Detector-Adapters-21028461-21028461/309522936

What?